Jan. 15, 1994
25 years ago: Gin Blossoms jangled to No. 1 on the Alternative Songs chart with "Found Out About You."
Jan. 16, 1988
The last No. 1 to date by a member of The Beatles topped the Billboard Hot 100, as George Harrison's "Got My Mind Set on You" (featuring Ringo Starr on drums) reached No. 1. Co-produced by ELO's Jeff Lynne, the song sparked the supergroup Traveling Wilburys – Harrison, Lynne, Bob Dylan, Roy Orbison and Tom Petty – which released two hit albums, in 1988 and 1990.
Jan. 17, 2015
Mark Ronson and featured vocalist Bruno Mars soared to their first of 14 weeks at No. 1 on the Billboard Hot 100 with their smash "Uptown Funk!" The song would go on to earn top honors as the No. 1 title on the year-end 2015 Hot 100.
(Six years earlier … on Jan. 17, 2009, Lady Gaga crowned the Billboard Hot 100 for the first time, as her debut entry, "Just Dance," featuring Colby O'Donis, spent its first of three weeks at No. 1. Stay tuned for more in-depth coverage this week on Billboard.com …)
Jan. 18, 1964
55 years ago, when Beatlemania began: The Beatles made their first appearance on a Billboard chart, as "I Want to Hold Your Hand" entered the Billboard Hot 100 at No. 45. The iconic song would go on to become the first of the Fab Four's record 20 Hot 100 No. 1s.
Jan. 19, 1980
Michael Jackson ruled the Billboard Hot 100 with "Rock With You." The song marked his first of nine No. 1s in the '80s, the most of any artist in the decade. (He totaled 13 career No. 1s as a soloist.)
Jan. 20, 1990
Michael Bolton banked the first new Billboard Hot 100 No. 1 of the '90s, as "How Am I Supposed to Live Without You" jumped 4-1. Laura Branigan had first taken the ballad to No. 12 in 1983.